Surface treatment compositions, such as fabric treatment compositions including laundry detergent compositions, typically comprise systems that deposit actives onto the surface to be treated. For example, laundry detergent compositions may comprise active components that need to be deposited onto the fabric surface before they can carry out their intended action. These active components include perfumes.
However, laundry detergent compositions are typically designed to remove material, i.e. soil, from the surface of a fabric during a laundering process. Therefore, the majority of the chemistry that is formulated into a laundry detergent composition is designed and tailored to carry out this task. Thus, it is difficult to deposit any active component onto a fabric surface during a laundering process due to this chemistry. This problem is especially true for active components that are liquid or liquefiable, such as perfumes, which are particularly troublesome to deposit onto a fabric surface during a laundering process.
Attempts have been made to improve the deposition of perfume onto a fabric surface during a laundering process by using hydrophobic perfume raw materials that have high boiling points; thus not readily evaporating from the wash liquor and more readily associating with the fabric surface due to having an increased hydrophobic interaction with the fabric surface. These perfumes are known as quadrant 4 perfume raw materials and are described in more detail in U.S. Pat. Nos. 5,500,138 and 6,491,728. However, the disadvantage of using quadrant 4 perfumes in laundry detergent compositions is that the perfumer is very limited in the choice of perfume raw materials that he can use, and the odours these quadrant 4 perfumes deliver are very musky odours that are not always suitable for use in laundry detergent compositions. In addition, the deposition of quadrant 4 perfumes onto the surface of a fabric during a laundering process is still not very efficient and still needs to be improved.
Other attempts to improve the fabric surface deposition of perfumes during a laundering process include the encapsulation of perfume raw materials, for example in starch to obtain a starch-encapsulated perfume accord. These starch-encapsulated perfume accords and their applications in laundry detergent compositions are described in more detail in WO99/55819. However, even when using these starch-encapsulated perfume accords in detergent compositions, although good wet stage odour can be achieved, perfume is still lost in the wash liquor during the laundering process, presumably being due to the fact that they are readily water-soluble and/or water-dispersible in the wash liquor.
Another approach is the loading of perfume onto porous carrier materials such as zeolite. This perfume-loaded zeolite approach is described in more detail in EP701600, EP851910, EP888430, EP888431, EP931130, EP970179, EP996703, U.S. Pat. Nos. 5,691,383, 5,955,419 and WO01/40430. However, there is a risk that the perfume may leak from the zeolite onto the detergent matrix during storage and/or leak into the wash liquor (i.e. before the zeolite has been deposited onto a fabric surface) during a laundering process. In order to overcome this problem, attempts have also been made to encapsulate these perfume-loaded zeolites with starch; this is described in more detail in EP859828, EP1160311 and U.S. Pat. No. 5,955,419. In co-pending European patent application 03252549.5 particles are described for improving efficiency of perfume deposition comprising a solid support such as zeolite supporting a liquid or liquefiable active component, that has a water-soluble and/or dispersible encapsulating material and in which a cationic polymer is adsorbed onto the water-insoluble solid support. The present inventors have now found that the performance of the particles described in this co-pending application may still be improved upon. The inventors have found that under stressed conditions the performance of these particles is diminished on storage and their studies have shown that this is due to hydrolysis of the cationic groups either diminishing the efficiency of the particle and/or resulting in undesirable by-products.
There is still therefore a need to increase the efficiency of delivery of active components incorporated in detergents, i.e. to improve the deposition of perfume and/or other liquid or liquefiable active components onto a fabric surface during a laundering process.